Toward mechanism- and gene-based therapies for retinal degeneration

寻找基于机制和基因的视网膜变性疗法

基本信息

批准号：
8337382
负责人：
Stephen H Tsang
金额：
$ 30.91万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-09-01 至 2014-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8337382
关键词：
Abbreviations Activities of Daily Living Address Adult Affect Age Age related macular degeneration Alleles Animal Model Animals Apoptosis Apoptotic Applications Grants BAC (bacterial artificial chromosome)Biochemical Birth Calcium Caring Cell Death Cell Survival Cessation of life Color Complex Cyclic AMP-Dependent Protein Kinases Cyclic GMP Data Defect Diagnosis Disease Electroretinography Equilibrium European Exhibits Eye GTP Phosphohydrolase Activators Gene Expression Gene Silencing Genes Genetic Recombination Genome Goals Growth Growth Inhibitors Guanylate Cyclase Health Histology Human In Situ Hybridization Individual Inherited Knock-in Mouse Knockout Mice Knowledge Lectin Light Macular degeneration Measurement Measures Mediating Methods Modeling Molecular Mus Mutagenesis Newly Diagnosed Night Blindness Nonexudative age-related macular degeneration Ophthalmologist Opsin Optometrist Pathogenesis Pathway interactions Patients Pattern Peanut Agglutinin Pharmaceutical Preparations Phase Phosphoglycerate Kinase Phosphorylation Phosphotransferases Photoreceptors Physiology Protein Kinase Proteins RNA Interference RNA Precursors Reporter Reporting Retina Retinal Retinal Cone Retinal Degeneration Retinal Diseases Retinitis Pigmentosa Ribosomal Protein S6 Rod Outer Segments Role Second Messenger Systems Signal Pathway Signal Transduction Sirolimus Staging Structure of retinal pigment epithelium Subfamily lentivirinae System Tamoxifen Testing Therapeutic Time Transgenes Translations Ursidae Family Vertebrate Photoreceptors Viral Vision cell growth clinically relevant cone-rod degeneration design diphtheria toxin fragment A early onset gene therapy genome wide association study human FRAP1 protein human TSC2 protein improved legally blind loss of function mTOR protein macula mouse model mutant novel novel therapeutics phosphoric diester hydrolase photoreceptor degeneration postnatal prevent promoter research study response retinal rods second messenger small hairpin RNA subretinal injection therapy development

项目摘要

DESCRIPTION (provided by applicant): About 36,000 cases of simplex and familial retinitis pigmentosa (RP) worldwide are due to defects in rod-specific PDE6, which consists of catalytic (PDE6a and PDE6b) and regulatory (PDE6g) subunits. In mouse models, low PDE6 activity leads to RP-like features. The Pde6brd1 null mouse exhibits dramatic elevation of retinal cGMP and rapid rod degeneration, which is complete within 3 weeks after birth. There are likely multiple changes in intercellular signaling induced by excessive cGMP, but the exact mechanisms underlying these pathways are unknown. A recently discovered weak Pde6b allele, H620Q, can further our understanding of early degeneration mechanisms and enable us to test novel therapeutic hypotheses. Like Pde6brd1 mice, Pde6bH620Q mutants show RP-like features and dramatic elevation of retinal cGMP. However, the time course of degeneration of Pde6bH620Q is significantly slower, with complete rod loss occurring after 6 weeks. Moreover, for the first three weeks after birth Pde6bH620Q display relatively normal rod histology and quantifiable rod physiology, which is not the case in Pde6brd1 mice. Our long-term goal is to use Pde6bH620Q mice to find therapies that inhibit the intracellular effects of excessive cGMP and/or enhance PDE6 specific activity to prevent further rod and cone degeneration. Aim 1. Establish if lower than normal PDE6 activity, combined with normal guanylate cyclase activity, results in elevated cGMP levels in Pde6bH620Qmutant mouse. Aim 2. Identify kinomic (kinases in the genome) survival and apoptotic effectors of cGMP rise in Pde6bH620Q mutants before morphological signs of degeneration. Such effectors will provide novel pharmacological targets to retard degeneration. Aim 3. Determine if progressive rod-cone degeneration can be genetically arrested by increasing PDE6 activity in Pde6b mutant rods. We intent to halt degeneration using Opsin::Pde6b rescue transgene and subretinal injections of Opsin::Pde6b rescue lentivirus. To test if the rod as well as gradual secondary cone loss can be arrested after the onset of rod death, we will employ a tamoxifen-inducible reverse Cre/loxP system to restore wild-type Pde6b in expression in mid-phase of the disease. PUBLIC HEALTH RELEVANCE: Inherited forms of retinal degeneration are incurable and affect about one in 2000 people; 1.5 million people worldwide are affected by retinitis pigmentosa (RP). Can the remaining rod and cone photoreceptor death be halted once degeneration has begun? Our proposal addresses a clinically relevant question, as most retinal degeneration patients have significant night blindness (rod death) when they are first seen by an optometrist/ophthalmologist. If one can impede further rod and cone loss by correcting the primary cause of the pathogenesis at the mid-stage of disease, then there is hope for a drug- or gene-based therapy to restore activities of daily living for newly diagnosed patients.

描述（由申请人提供）：全世界大约36,000例单纯形和家族性视网膜色素（RP）归因于杆特异性PDE6的缺陷，该缺陷由催化（PDE6A和PDE6B）和调节（PDE6G）组成。在鼠标模型中，低PDE6活性导致类似RP的特征。 PDE6BRD1 null小鼠表现出视网膜CGMP和快速杆变性的显着升高，这在出生后3周内完成。过度CGMP引起的细胞间信号传导可能有多种变化，但是这些途径的确切机制尚不清楚。最近发现的弱PDE6B等位基因H620Q可以进一步了解我们对早期变性机制的理解，并使我们能够检验新的治疗假设。像PDE6BRD1小鼠一样，PDE6BH620Q突变体显示出类似RP的特征和视网膜CGMP的显着升高。但是，PDE6BH620Q的变性时间较慢，在6周后发生完全的杆损耗。此外，在出生后的前三周，PDE6BH620Q表现出相对正常的杆组织学和可量化的杆生理学，这在PDE6BRD1小鼠中并非如此。我们的长期目标是使用PDE6BH620Q小鼠找到抑制过度CGMP和/或增强PDE6特异性活性的细胞内影响的疗法，以防止进一步的杆和锥变性。 AIM 1。确定是否低于正常PDE6活性，结合正常的鸟苷酸环化酶活性，导致PDE6BH620QMMUTANT小鼠的CGMP水平升高。 AIM 2。鉴定基因组中的激酶（激酶）在形态变性迹象之前，PDE6BH620Q突变体中CGMP的生存和凋亡效应子。这种效应子将为延迟变性提供新的药理靶标。 AIM 3。确定是否可以通过增加PDE6B突变棒中的PDE6活性来遗传循环杆锥变性。我们打算使用OPSIN :: PDE6B救援转基因和视网膜下注射OPSIN :: PDE6B救援慢病毒的视网膜下注射。为了测试杆死亡发作后是否可以停止杆和逐渐的二级锥体损失，我们将采用他莫昔芬诱导的反向Cre/Loxp系统来恢复疾病中期表达中野生型PDE6B。公共卫生相关性：视网膜变性的遗传形式是无法治愈的，并影响了2000年的大约1人；全球150万人受到色素性视网膜炎（RP）的影响。一旦变性开始，剩余的杆和锥形感受器死亡是否可以停止？我们的提案解决了一个与临床相关的问题，因为大多数视网膜变性患者在验光师/眼科医生首次看到时都有明显的夜失明（ROD死亡）。如果人们可以通过纠正疾病中期的发病机理的主要原因来阻碍杆和锥体损失，那么人们希望有一种基于药物或基因的治疗来恢复新诊断的患者日常生活活动。